This is what I usually make for myself.
Take some cantaloupe and honey dew melon and cut into bite sized pieces into a bowl with a lid, discarding the rinds. Add some green seedless grapes and whatever berries you can find in season (strawberries or blueberries are great) and mix together or in the winter I add chunks of canned pineapple or mandarin oranges (packed in water, not syrup)
I keep this in the fridge and take some to work or eat some at breakfast. For more substance you can add low fat vanilla yogurt and some granola on top or mix with low fat vanilla pudding